Power-operated wrench



Feb. 7, 1967 a. c. MITCHELL ETAL POWER" OPERATED WRENCH 2 Sheets-Sheet 1 Filed Oct. 23, 1964 [N VENTORS w M W E 0 M m c A V v mi Mam pfi CW W Y d Feb. 1967 c. c. MITCHELL ETAL 3,302,496

POWER- OPERATED WRENCH 2 Sheets-Sheet 2 Filed Oct. 23 1964 FIG.2.

INVENTOJEJ C. C. MITCHELL W. D. STEVENSON Wm, 7% 9 m A TTORNEYS' United States Patent 3,382,496 POWER-OPERATED WRENCH Colin Campbell Mitchell and William David Stevenson, Edinburgh, Scotland, assignors to ENJRJD. Limited, London, England, a British company Filed Oct. 23, 1964, Ser. No. 4tl6,(i73 Claims priority, application Great Britain, Oct. 25, W63, 42,209/63 Claims. (Cl. 8l53) This invention relates to earth borehole drilling or like rigs in which lengths of tubular members, such as drill pipes, are required to be made together to form a string for some operation, such as drilling, to be performed and subsequently withdrawn in succession from the string, the individual lengths being made together by a screwing action, one end of one length being screwed into the end of the next, possibly with the aid of intermediate connecting members. If power is transmitted through the string for operational purposes, as in the drilling operation in a drilling rig, great force may be necessary in breaking the joints when dismantling the string and power means have to be used for the operation of unscrewing the lengths of the string. Such power means may also be used in the operation of making the lengths together.

A number of different proposals have been made for such power means, including one in which two togglegripping devices, with hydraulic actuators, are adapted to clamp themselves, one to each part of the joint, hydraulic ram means being provided to act between the two devices to rotate them relative to each other to crack the joint. The present invention has for one of its objects to provide power means of this nature which is of more compact construction.

In accordance with the invention, power means for making and/ or breaking a twist joint between two members, comprises interacting members adapted for rotation relative to one another and each carrying or incorporating gripping devices for gripping one or other part of the joint, one or other of said interacting members being provided with at least one vane or the like, said vane extending into a co-operating passage associated with the other of said interacting members, arrangements being made for actuating fluid to be introduced into said co-operating passage to one side or the other of the vane extending thereinto, so as to cause relative movement between the two interacting members and thereby to cause relative movement between the parts of the twist joint.

In a preferred construction a plurality of co-operating vanes and passages are provided, and these are substantially symmetrically disposed around the axis of relative rotation of the parts of the power means, and it is preferably arranged that the fluid supplies to these passages are in parallel so as to react substantially simultaneously and uniformly on the respective vanes.

The gripping devices carried by the interacting members may be hydraulically-operated and are preferably substantially symmetrically disposed around the axis of relative rotation of the parts of the power means. The gripping devices may then comprise hydraulic cylinders with co-operating pistons, the pistons carrying friction pads for engagement with the parts of the twist joint. Such friction pads may be mounted directly onto the piston members themselves; they may be serrated and are preferably of toughened material.

By arranging that the interacting members of the power means overlap axially, the said co-operating vanes and passages may be formed radially; and thereby an even more compact arrangement may be devised.

In order that the invention may be more clearly understood, one embodiment thereof in a power means for operation on the screwed joints of an earth borehole drilling rig pipe string will now be described with reference to the accompanying drawings.

In the drawings, FIGURE 1 is a part-sectional view in the direction of the axis of relative rotation of the members of the power means; FIGURE 2 is a part-sectional view on the line II-II in FIGURE 1; and FIGURE 3 is a partial side view in the direction of the arrow III in FIGURE 1.

The parts 1 and 2 of the power means, which interact to move relatively to each other about the axis 3, overlap each other in the axial direction, the part 1 being formed with an annular groove 4 into which projects an annular flange 5 projecting from the part 2. Grooves 6 and 7 in the respective parts are arranged to co-operate to provide a passage via ducts 8 and 9 from one part of the power means to the other, packings Ill and Ill sealing these grooves against leakage of actuating fluid fed through this passage.

The flange 5 is provided with five wall members 12, symmetrically spaced and each is arranged to project radially across the peripheral slot 113 formed in the flange. Each member 12 is positioned between vane members 14 which are also symmetrically spaced around the inner periphery of, and which project inwardly from, the part 1 into sliding contact with the walls of the slot in the flange 5; slot 13 is, in effect, in five parts around the periphery of the part 1 with one vane member 14 extend ing into each part. Each vane member 14 is secured to member 1 by means of bolts 30.

Ducts l6 and 17 are arranged in communication with holes 31 and 32, respectively, in the wall of groove 4, the holes 31, 32 leading to the ends of each part of the slot 13, these ducts terminating in pipe connections 18 and 19 respectively through which actuating oil may be fed to or returned from these slots to cause reaction of oil pressure against one face or other of each vane member 14, or relief of pressure, as required. If the part 1 of the power means is fixed, then part 2 will be rotated in one direction or the other accordingly; there is no necessity, however, for either part to be fixed except, as will be described, to the drill pipes which are screwed together.

In order to grip the two drill pipes (indicated at 20 and 21) each part of the power means is provided with hydraulic rams 22 as indicated; four such rams, symmetri cally dispose-d about the drill pipes, are shown provided on each part, but it will be appreciated that any number more than two may be providedas necessary. These rams are preferably canted in sets towards each other as indicated. Each piston 23 carries a friction pad 24 which is of a serrated construction and is faced with material known under the registered trademark Stellite; this pad may be attached to the end of the piston. It should be noted that the showing of the gripping pistons is incomplete in the drawings.

The pistons are operated by introducing pressurised fluid into the cylinders through respective pipe connections 25, 26, a supply vent hole 27 being provided for the purpose of introduction of actuating fluid from the supply pipe 29 through the hollow stem 28 to act on a secondary piston when it is desired to release the power means from the drill pipes.

It will be observed that, to operate the power means, it may be introduced to the drill pipe string as the latter is being raised and may be automatically positioned at a joint between drill pipes; actuating fluid is first applied to the pistons 23, preferably in parallel circuits until sufiicient power has been developed to grip each part of the joint between the drill pipes firmly between four friction pads. Thereupon actuating fluid is directed through the appropriate pipes 18 or 19 to cause relative rotation of the parts 1 and 2 which, of course, brings about relative rotation of the adjacent drill pipes to crack the screwed .3: joint between them, ready for the upper drill pipe to be spun oif by some auxiliary device after the grip of the power means has been released by retraction of the pistons 23. Making of a joint will be effected in a similar manner, as will be readily understood.

It will be noted that by manipulation of the power means, by systematic release and re-connection of the gripping mechanism after suitable return rotation of the two parts of the power means, the power means may be arranged to unscrew the joint as much as desired (or, of course, alternatively to make firm from as loose a joint as desired).

It will be appreciated that by the axial overlap of the two parts of the power means, a very compact arrangement results; also, by the device of canting the gripping pistons, it can be arranged that the two parts of the drill pipe joint are gripped close to the joint.

Obviously other frictional means may be used to pro vide sufficient frictional force to avoid slipping of the gripping pistons during operation and, possibly, it may be arranged that any such slipping may cause an increase in hydraulic pressure on the pistons, to counteract itself.

Further, it will be apparent that a power means of the kind described lends itself readily to automation. Thus the power means may be used in a fully automated drilling rig, for example, where drill pipe sections are introduced and made together or pulled out and removed using reciprocal hydraulic lifts to one of which lifts the power means may be arranged to be introduced at the appropri' ate drilling or pulling stage.

It will also be appreciated that a small version of such power means may be useful in making or breaking joints between small pipes which may resist breaking by other means.

We claim:

1. Power means for making and breaking a twist joint between two members, comprising two interacting assemblies adapted for rotation relative to one another about the common axis of said twist joint and each having gripping devices, one for gripping one of said members and the other for gripping the other member, one of said interacting assemblies being provided with at least one vane member extending into a co-operating arcuate passage formed in the other of said interacting assemblies, and means for introducing actuating fluid into said cooperating passage to one side of said vane member to cause powered relative movement in one sense between said vane member and an end wall of said passage to cause relative movement between said two assemblies, and therefore between said two members, to make said twist joint between them, and to the other side of the vane member to cause powered relative movement in the opposite sense between said two assemblies, and therefore between said two members, to break said twist joint.

2. Power means as claimed in claim 1, including a plurality of co-operating vanes and passages substantially symmetrically disposed around said common axis.

3. Power means as claimed in claim 2, wherein fluid is supplied to said passages in parallel so as to react substantially simultaneously and uniformly on the respective vanes.

4. Power means as claimed in claim 1, including means for hydraulically operating said gripping devices.

5. Power means as claimed in claim 1, wherein said gripping devices are substantially symmetrically disposed around said common axis.

6. Power means as claimed in claim 4, wherein said gripping devices comprise hydraulic cylinders with cooperating pistons, each piston carrying a friction device for engagement with one part of the twist joint.

7. Power means as claimed in claim 6, wherein said friction device comprises at least one friction pad mounted directly onto said piston member itself.

8. Power means as claimed in claim 7, wherein said friction pad is serrated and of toughened material.

9. Power means as claimed in claim 2, wherein said interacting assemblies overlap axially, said co-operating vanes and passages being radially disposed with respect to said common axis.

10. Power means for operating on members joined by a twist joint, comprising at least two interacting members, said interacting members being adapted for rotation relative to one another about the common axis of said joint, a gripping device associated with each of said interacting members for gripping a part of the joint, at least one vane member associated with some of said interacting members and at least one arcuate passage associated with the other of said interacting members, said arcuate passage being concentric with said common axis, said vane extending into said passage and co operating therewith, and means for supplying actuating fiuid to said passage on either side of the vane extending thereinto so as to cause relative movement between said interacting members about said axis.

References Cited by the Examiner UNITED STATES PATENTS 2,332,685 10/1943 Auld et al. 81-57 2,453,369 11/1948 Grable et al. 81-54 2,536,458 1/1951 Munsinger 8157 2,566,561 4/1951 Edelberg 8l53 2,705,614 4/1955 McKibben et al. 8157 3,041,901 7/1962 Knights 8153 WILLIAM FELDMAN, Primary Examiner.

JAMES L. JONES 111., Examiner. 

1. POWER MEANS FOR MAKING AND BREAKING A TWIST JOINT BETWEEN TWO MEMBERS, COMPRISING TWO INTERACTING ASSEMBLIES ADAPTED FOR ROTATION RELATIVE TO ONE ANOTHER ABOUT THE COMMON AXIS OF SAID TWIST JOINT AND EACH HAVING GRIPPING DEVICES, ONE FOR GRIPPING ONE OF SAID MEMBERS AND THE OTHER FOR GRIPPING THE OTHER MEMBER, ONE OF SAID INTERACTING ASSEMBLIES BEING PROVIDED WITH AT LEAST ONE VANE MEMBER EXTENDING INTO A CO-OPERATING ARCUATE PASSAGE FORMED IN THE OTHER OF SAID INTERACTING ASSEMBLIES, AND MEANS FOR INTRODUCING ACTUATING FLUID INTO SAID COOPERATING PASSAGE TO ONE SIDE OF SAID VANE MEMBER TO CAUSE POWERED RELATIVE MOVEMENT IN ONE SENSE BETWEEN SAID VANE MEMBER AND AN END WALL OF SAID PASSAGE TO CAUSE RELATIVE MOVEMENT BETWEEN SAID TWO ASSEMBLIES, 